ATR4251 Datasheet, PDF (12/21 Pages) ATMEL Corporation – Low-noise, High-dynamicrange AM/FM Antenna Amplifier IC

9. Application Circuit (Demo Board)
Figure 9-1. Common Base Configuration
VB+ 10
GND
R23
4.7Ω ^{+ C26 C23}
10 µF 100 nF
R24
180 nH
4.7Ω ^{+ C27 C24}
L3
10 µF 100 nF
AM/FM application combined with AM AGC
with the following capability
1. Testing FM + FM AGC
connector FM as input
connector AM/FM_OUT as output
2. Testing AM + AM AGC
connector AM as input
connector AM/FM_OUT as output
AM/FM_OUT
+VS
C30 C21
100 nF 2.2 µF
C17
R21
100Ω
2.2 pF
(4)
C19
33 pF
C18
1 pF⁽⁴⁾
100 nF C20
470 nF
C31
R20
33Ω⁽¹⁾
L3
470 nH
C12
1 nF
R11⁽²⁾
10 kΩ
+VS
R10
100Ω
T2
BC858
C13
220 nF
C33
+
4.7 µF
R12⁽²⁾
2.2 kΩ
R3
1 kΩ
C28
1 pF
C29
2.2 nF
C2
2.2 nF
D1
BA679
C5
2.2 nF
FM
AM
6
4
TR1
1
3
D2
BA679
R7
(2)
C6
10 nF
+VS
R2
51Ω
C1
2.2 pF
R1
47Ω
L1
120 nH
C3 ^{R6 R5}
100 nF
C4 _RS1
2Ω
22 pF
100Ω ⁽²⁾
T1
BC858
C11
100 pF
12 ATR4251
D3
BA779-2
R25
R4
68Ω
4.7 MΩ
C7
1 µF
+ _C32
10 µF
C10
220 nF 15 nF
C8
1 nF
R8
3 kΩ⁽³⁾
R9
10 kΩ⁽³⁾
(1) AM Output impedance
(50Ω adjustment)
(2) Leakage current reduction
(3) AM AGC threshold
(4) AM AGC threshold
4913I–AUDR–03/08